Canine Ehrlichiosis (Tropical Canine Pancytopenia): Survival of Phosphorus-32-Labeled Blood Platelets in Normal and Infected Dogs

Abstract

SUMMARY The fate of diisopropyl fluorophosphate 32 P ( df 32 P)-labeled blood platelets was examined in normal and thrombocytopenic Ehrlichia carcis -infected dogs. Platelet survival in normal dogs was 10.9 days, with minimum and maximum of 9.7 and 12.0 days (mean ± 2 S y,x ). Platelet survival in chronically infected thrombocytopenic dogs was 7.0 days, with minimum and maximum of 5.6 and 8.4 days (mean ± 2 S y,x ). Platelet survival of infected dogs during the acute phase of infection consisted of an initial phase, during which 50% of labeled platelets was lost over a 12-hour period, and a subsequent linear phase. Platelet survival during the latter phase was similar to that of chronically infected dogs. Although accelerated platelet destruction may contribute to thrombocytopenia during the acute phase of E. canis infection, the reduction in platelet survival in chronically infected dogs is not sufficient to explain the degree of thrombocytopenia observed. It is suggested that bone marrow hypoplasia may be involved in the disease syndrome.